Homicide detective John Hobbes witnesses the execution of serial killer Edgar Reese. Soon after the execution the killings start again, and they are very similar to Reese's style.
Det. John Hobbes is convinced that when killer Edgar Reese is executed, all of his troubles are over. But when people he knows and people on the street start to sing the same tune that Reese sang in the gas chamber, and those same people taunt him, he is told that maybe the cursed fallen angel Azazel is behind it all. Azazel is cursed to roam the Earth without a form, and he can switch bodies by any contact, making him hard to track. When Hobbes is forced to kill a man possessed by Azazel, he must clear his name while protecting his family and others from the evil, vengeful Azazel.
Detective John Hobbes has captured and imprisoned the crazy serial killer Edgar Reese, then Reese was brought to execution by gas chamber. Hobbes thought his nightmare with this killer is finally over. However, he soon discovers that there was a murder in a style very similar to Edgar Reese. Then, he found out that it was an evil fallen angel named Azazel, who can exist by possessing other people's bodies. As Hobbes tries to find out the mystery of Azazel, he also has to find a way to do the impossible, stop a fallen angel.
Detective John Hobbes attends the execution of a serial killer he arrested, Edgar Reese. They have a private chat where Reese gives him a riddle of sorts and then speaks in a strange language. The riddle leads him to a once decorated policeman who one day went to his cottage in the woods and killed himself. It was never explained why but when Hobbes looks around the now decrepit cottage he finds that the man had scribbled the name Azazel on the wall. Hobbes soon learns that Azazel is an evil spirit who can transfer itself from one person to another through touch. As Hobbes comes to realize the extent Azazel is responsible for much of the evil around him he also realizes that Azazel is after him.
John Hobbes watches Edgar Reese, a convicted murderer Hobbes brought to justice, get executed. Reese dies with great bravado, and then a series of murders are committed using Reese's methods. As Hobbes follows up the last clues Reese left, we see an evil presence move from person to person by touch. Hobbes comes closer and closer to the secret as the presence taunts him more and more openly, threatening everyone Hobbes holds dear in the world.
- Homicide detective John Hobbes (Denzel Washington) and Edgar Reese (Elias Koteas), a serial killer, are talking just before the latter is going to be executed in prison. Reese is proud of all his crimes, and doesn't repent at all. Hobbes witnesses the execution of Reese. At the last second, Reese starts shouting that he is innocent, that it wasn't him, all his cocky demeanour lost.
However, this doesn't finish the matter. Soon after the execution the killings start again, and they are very similar to Reese's style. Hobbes starts hearing people on the street singing the same tune that Reese sang in the gas chamber.
He is told that maybe the fallen angel Azazel is behind it all. Azazel is cursed to roam the Earth without a form, and he can switch bodies by any contact, making him hard to track. The last clue is given by Gretta Milano (Embeth Davidtz), a semi-mad woman who lives in a flat crammed with bric-a-brac, pictures, and small statues representing all kind of of angels. When Hobbes is forced to kill a man possessed by Azazel, he must clear his name while protecting his family and others from the evil, vengeful Azazel. Milano tells him to kill Azazel in a place where no other person is around. If Hobbes kills the person who is at the moment possessed by Azazel, and he himself commits suicide, the fallen angel will die, because he can't survive for long without a body.
Hobbes is determined. His workmates are suspicious of him. They think that he has tricked them all, being the serial killer from the very beginning, or that he has become so obsessed with the serial killer that now he's copy-cattting him. His co-worker and closest friend, Det Jonesy (John Goodman), is one of those who seem to have changed their minds concerning Hobbes. Lou and Stanton (James Gandolfini and Donald Sutherland) start having no doubts that Hobbes is the killer.
Hobbes goes to a lonely cottage kilometers away from nowhere where he has dared Azazel to go. To his surprise, it's Jonesy who goes. He tells him that it was about Hobbes from the beginning. When Hobbes and Reese had the conversation, there was a second when they shook hands, but Azazel could not move inside Hobbes because he was an honest and good person. There is a final confrontation and Hobbes kills Jonesy, and then kills himself.
It seems that evil has died. However, a voice tells the audience that there is only an animal which can hold a demon, a cat. We see a cat which is making its way to the nearest inhabited town. The audience now knows that Hobbes didn't succeed.